Carbon dots (CDs) are a new cluster of carbon atoms with particle size less than 10 nm. CDs also exhibit interesting fluorescence (FL) properties. CDs are attractive because of their fascinating characteristics including low toxicity, good water solubility, and tremendous biocompatibility. Recently, CDs have been investigated as biosensors for numerous target analytes. Meanwhile, the utilization of cheap and renewable natural resources not only fulfills the pressing requirement for the large-scale synthesis of CDs but also encourages the establishment of sustainable applications. The preparation of CDs using natural resources, i.e., plants, offers several advantages as it is inexpensive, eco-friendly, and highly available in the surroundings. Plant parts are readily available natural resources as the starting materials to produce CDs with different characteristics and attractive applications. Several review articles are now available covering the synthesis, properties, and applications of CDs. However, there is no specific and focused review literature discussing plant part-derived CDs for biosensing applications. To handle this gap, we provide a review of the progress of CDs derived from various plant parts with their synthesis methods, optical properties, and biosensing applications in the last five years. We highlight the synthesis methods and then give an overview of their optical properties and applications as biosensors for various biomolecules and molecules in biological samples. Finally, we discuss some future perspectives for plant part-derived CDs for better material development and applications.

Carbon dots (CDs) have generated much interest because of their significant fluorescence (FL) properties, extraordinary photophysical attributes, and long-term colloidal stability. CDs have been regarded as a prospective carbon nanomaterial for various sensing applications because of their low toxicity, strong and broad optical absorption, high chemical stability, rapid transfer properties, and easy modification. To improve their functionality, CD/polymer composites have been developed by integrating polymers into CDs. CD/polymer composites have diversified because of their easy preparation and applications in sensing, optoelectronics, semiconductors, molecular delivery, and various commercial fields. Many review articles are available regarding the preparation and applications of CDs. Some review articles describing the production and multiple applications of the composites are available. However, no such article has focused on the types of precursors, optical properties, coating characteristics, and specific sensing applications of CD/polymer composites. This review aimed to highlight and summarize the current progress of CD/polymer composites in the last five years (2017–2021). First, we overview the precursors used for deriving CDs and CD/polymer composites, synthesis methods for preparing CDs and CD/polymer composites, and the optical properties (absorbance, FL, emission color, and quantum yield) and coating characteristics of the composites. Most carbon and polymer precursors were dominated by synthetic precursors, with citric acid and polyvinyl alcohol widely utilized as carbon and polymer precursors, respectively. Hydrothermal treatment for CDs and interfacial polymerization for CDs/polymers were frequently performed. The optical properties of CDs and CD/polymer composites were almost identical, denoting that the optical characters of CDs were well-maintained in the composites. Then, the chemical, biological, and physical sensing applications of CD/polymer composites are categorized and discussed. The CD/polymer composites showed good performance as chemical, biological, and physical sensors for numerous targets based on FL quenching efficiency. Finally, remaining challenges and future perspectives for CD/polymer composites are provided.

Purslane is a plant that thrives in open areas and has a fairly high water content. Hereditary purslane plant has been used for skin protection from the sun. The aim of this study is to determine the value of Sun Protecting Factor (SPF) of ethanol extracts, soluble and insoluble fractions of ethyl acetate from purslane herb.Extraction using maceration method by ethanol 90%. Fractionation process is the partition obtained soluble and insoluble fractions of ethyl acetate. Absorbance values read using UV-VIS spectrophotometry at a wavelength of 290-320 nm. SPF value is obtained for the ethanol extract 19.495, 20.829 for the soluble fraction of ethyl acetate and 30.055 for an insoluble fraction of ethyl acetate.

Serangan Organisme Pengganggu Tanaman (OPT) pada tanaman padi apabila tidak ditangani dengan serius akan menurunkan produktivitas tanaman secara signifikan. Keragaman OPT yang menyerang tanaman padi varietas lokal dan varietas unggul baru (VUB) sangat penting untuk diketahui agar dapat dilakukan tindakan pengendalian yang lebih efektif dan efisien. Penelitian dilaksanakan pada bulan Agustus sampai Februari 2018, di Teaching Farm Fakultas Pertanian Universitas Hasanuddin Makassar. Metode yang digunakan pada percobaan semi lapangan ini dengan mengamati secara langsung jenis OPT yang menyerang rumpun tanaman padi, gejala serangan yang ditimbulkan serta menghitung persentase serangan. Pengamatan dilakukan setiap hari, dimulai pada saat tanaman berumur ± 30 hari setelah tanam. Hasil penelitian menunjukkan bahwa OPT yang menyerang VUB dan varietas lokal yaitu Locusta migratoria. L, Sesamia inferens, Cnaphalocrosis medinalis serta patogen penyakit hawar daun bakteri (HDB). Persentase serangan tertinggi terdapat pada VUB Inpari 16 dan Inpari 42 yang terserang HDB mencapai 50% sedangkan varietas lokal Kamba yang diamati memiliki reaksi ketahanan yang agak baik terhadap berbagai serangan OPT dengan persentase serangan ≤25%. Serangan Nilaparvata lugens hanya ditemukan pada varietas Inpari 16. Hasil penelitian ini dapat dijadikan referensi dan sumber informasi agar pengelolaan dan tehnik pengendalian dapat dilakukan secara tepat, cepat, efisien dan efektif.

Abstract. Sudewi S, Ala A, Baharuddin, Farid M. 2020. The isolation, characterization endophytic bacteria on from roots of local rice plant Kamba in Central Sulawesi, Indonesia. Biodiversitas 21: 1614-1624. The local Kamba rice plants are cultivated by the Bada Valley people for generations by obtaining seeds from previous crops. This rice plant is able to survive even though it is cultivated with traditional cultivation techniques. The ability to survive is suspected because this local rice plant is associated with endophytic bacteria through a variety of mechanisms including being able to produce the IAA hormone and its ability to dissolve phosphate. This study aims to find endophytic bacteria that have the potential to produce IAA and phosphate solvents through morphological and physiological characterization (Gram reaction test with 3% KOH, catalase test, hypersensitivity reaction and hemolysis activity), screening of IAA-producing bacteria qualitative and quantitative, phosphate dissolution activity on Pikovskaya medium, and quantitative using a spectrophotometer. Endophytic bacteria isolates from Gintu give the highest yields in IAA production and phosphate solubility activity, namely RKGU11 and RKGU6, respectively at 4,905 mg L-1 and 10.984 mg L-1 so that it has the potential to be used as a candidate for biofertilizer agents in developing effective sustainable agriculture, respectively, efficient and environmentally friendly.

Algae are a place to live for various microorganisms’ symbiosis with them, and some of them were known to be used as antibacterial. This study aims to determine the antibacterial activity of associated bacteria isolates from Turbinaria ornata algae obtained from the Bay of Manado against Staphylococcus aureus and Escherichia coli bacteria. In the course of testing the isolation and purification of symbiotic bacteria from Turbinaria ornata algae, then antibacterial activity was testing using agar diffusion method, then gram staining and biochemical tests were carried out including motility test,  tets, carbohydrate fermentation test, citrate test, lysine test, indole test and catalase test. The result showed  that there were 3 bacterial isolates, which had antibacterial activity in medium category against S.aureus and E.coli bacteria. Based on the results of biochemical identification, the isolates that have the greatest inhibitory power, they were thought to belong to genus Bacillus and the genus Yersinia.Keywords : Antibacterial, Symbionic bacteria, Turbinaria ornata (Turner) J.   Agardh. ABSTRAK Alga merupakan tempat hidup berbagai mikroorganisme yang bersimbiosis dengannya, dan beberapa dari spesies alga diketahui sering dimanfaatkan salah satunya  sebagai antibakteri. Penelitian ini bertujuan untuk mengetahui adanya aktivitas antibakteri dari isolat bakteri yang berasosiasi dengan alga Turbinaria ornata yang diperoleh dari Teluk Manado terhadap bakteri  Staphylococcus aureus dan Escherichia coli. Dalam pengujian dilakukan isolasi dan purfifikasi bakteri simbion dari alga Turbinari ornata, kemudian dilakukan pengujian aktivitas antibakteri menggunakan metode difusi agar, selanjutnya silakukan pewarnaan gram dan uji biokimia meliputi uji motilitas, uji H2S, uji fermentasi karbohidrat, uji sitrat, uji lisin, uji indol dan uji katalase. Hasil penelitian menunjukkan bahwa terdapat 3 isolat bakteri yang mempunyai daya aktivitas antibakteri dalam kategori sedang terhadap bakteri S. aureus dan E. coli. Berdasarkan hasil identifikasi secara biokimia isolat yang mempunyai daya hambat paling besar diduga termasuk dalam genus Bacillus dan genus Yersinia. Kata kunci : Antibakteri, Bakteri simbion, Turbinaria ornata (Turner) J. Agardh.

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In this study, new nitrogen-doped carbon dots (N-CDs) were prepared by utilizing rambutan seed waste and l-aspartic acid as dual precursors (carbon and nitrogen sources) through a hydrothermal treatment method and applied as a fluorescent sensor toward Congo red.